Abstract

We will begin by scheduling talks for this term, and then Francesco will give his talk:

Many large software systems originate from untyped scripting language code. While good for initial development, the lack of static type annotations can impact code-quality and performance in the long run. We present an approach for integrating untyped, or dynamically typed, code and typed code in the same system to allow an initial prototype to be smoothly evolved into an efficient and robust program. Our approach adds like types, a novel intermediate point between dynamic and static typing. Locally to their scope, like types variables are checked statically, but as they may be bound to dynamic values their usage is checked dynamically. Thus like types provide some of the benefits of static typing without substantially decreasing the expressiveness of the language. We provide a formal account of like types in a core object calculus and evaluate their applicability in the context of a new scripting language.

Collaboration with T. Wrigstad, S. Lebresne, J. Ostlund, J. Vitek (Purdue University).